When a vehicle is involved in a collision an airbag may be deployed to cushion an impact between an occupant of the vehicle and an interior object or surface, such as a steering wheel, or a window.
The airbag is inflated to form a cushion, which often has a constant pressure and constant tension over its surface. The tension in the surface of the cushion increases as the occupant impacts the cushion. The pressure and tension can be reduced by venting gas out of the cushion.
The tension in the surface of the cushion may be tailored according to the size and weight of the occupant. Smaller occupants may be cushioned more effectively by lower surface tension cushions; whereas higher surface tensions may be required to cushion the impact of larger occupants, or an occupant who is not wearing a seat belt.